【摘要】 蛇类是一种研究能量平衡的模型动物,而肠道微生物则帮助宿主获取能量和营养。大多数肠道微生物的研究集中在圈养动物上,而对于野生蛇类的研究很少。本研究从3只野生虎斑颈槽蛇(Rhabdophistigrinus)的大肠、小肠和泄殖腔内容物提取微生物总DNA,进行16SrRNA基因V4区域扩增子测序,分析虎斑颈槽蛇肠道核心微生物组成和分布特征。结果表明,阿尔法指数在不同肠道区域的多样性不存在显著性差异。大肠、小肠和泄殖腔3个肠道部位共享534个操作分类单元(OTUs),大肠包含最多特有OTUs(388个)。门水平,梭杆菌门(Fusobacteria)在小肠(52.87%±14.49%)、大肠(41.12%±22.60%)和泄殖腔(65.70%±10.44%)均为优势菌。属水平,鲸杆菌属(Cetobacterium)在小肠(46.36%±13.86%)、大肠(21.95%±9.82%)和泄殖腔(58.18%±14.29%)为优势菌,柠檬酸杆菌属(Citrobacter)在小肠和泄殖腔中有显著性差异。此外,在其肠道检测到很多潜在的致病菌,例如,柠檬酸杆菌属、明串珠菌属(Trichococcus)和丹毒丝菌属(Erysipelothrix),了解了潜在致病菌在虎斑颈槽蛇肠道中的分布情况。在聚类分析中发现泄殖腔的数据重复性较好,将本研究泄殖腔数据与前人研究过的食鱼蝮(Agkistrodonpiscivorus)泄殖腔高通量测序数据进行联合分析,为更广泛开展不同蛇类肠道微生物组成的差异性分析提供理论借鉴依据。更多还原

【Abstract】 Snakes are model animals for studying vertebrate energy balance. The gut microbes help the host get energy and nutrients. Currently, researches focused on the captive animals, but little is known about the gut microbes in the wild snakes. We described intestinal microflora in large intestine, small intestine and cloaca in 3 wild Rhabdophis tigrinus by using a V4 region of 16 S rRNA gene amplicon sequencing and analyzed the core composition and distribution characteristics of the intestinal microflora. The results showed no significant difference in the diversity of alpha index in different intestinal regions(Table 1). The three intestinal regions shared 534 Operational Taxonomic Units(OTUs), among which the large intestine contained388 more unique OTUs(Fig. 3 c). At the phylum level, Fusobacteria were found to be dominant in the small intestine(52.87% ± 14.49%), large intestine(41.12% ± 22.60%) and cloaca(65.70% ± 10.44%)(Fig. 1). At the genus level, we indicated that the genus of Cetobacterium had an advantage in all intestinal segments,including the small intestine(46.36% ± 13.86%), large intestine(21.95% ± 9.82%) and cloaca(58.18% ±14.29%)(Fig. 2), and that Citrobacter showed a significant difference between small intestine and cloaca. In addition, many potentially pathogenic bacteria, for example, Citrobacter, Trichococcus and Erysipelothrix,were detected in the gut, which is helpful for. understanding the distribution of potential pathogens in the intestines of Rhabdophis tigrinus. In cluster analysis, the data repeatability of cloaca samples were well(Fig.3 d) and combined analysis with the Agkistrodon piscivorus data provided the theoretical basis for further comparison analysis of intestinal microflora among different snake species(Fig. 4).更多还原